Offset printing is a printing technique which has been used for many years; and, in the course of printing, foreign particles of dried ink, paper, dirt, and the like, cause inked spots on the finished copy. These foreign particles are popularly referred to by printers and others in the printing industry as "hickeys", and various techniques have been proposed for removal of these hickeys from printing plates, including the use of rollers referred to as "hickey rollers".
The "hickey rollers" proposed heretofore are considered as being generally deficient. For example, some of such previously proposed hickey rollers tend to absorb excessive amounts of ink while being operated to remove hickeys causing defective printing, others of such previously proposed rollers must be removed from their associated press for cleaning, and still others require special (and usually expensive) maintenance to keep them operative.